[Studies on genotype of human cytomegalovirus glycoprotein H from infantile clinical isolates].

OBJECTIVE

To investigate the genetic polymorphism of human cytomegalovirus (HCMV) glycoprotein H (gH) from infantile clinical isolates, to analyze the genotypic distribution of gH in different diseases of HCMV infection and try to find the correlations between the diseases and genotypes.

METHOD

Fresh urine specimens were collected from the hospitalized children with different diseases whose blood HCMV-IgM and HCMV-IgG were positive. Virus was isolated from these specimens. Glycoprotein H of harvest clinical isolates was genotyped by nested-PCR combined with restriction fragment length polymorphism (RFLP), the purified PCR products were digested by restriction endonuclease HhaI. The digested products were genotyped by polyacrylamide gel electrophoresis and silver staining. Classification and results of sequencing were compared.

RESULT

Totally 102 HCMV clinical isolates were obtained. Glycoprotein H gene of these clinical isolates (43 cases had infantile hepatitis syndrome, 38 cases had anicteric hepatitis, 13 pneumonia, 7 thrombocytopenic purpura, and 1 congenital CMV infection) were positive by nested-PCR, whose positive rate was 100%. The results showed that 62 strains were gH1 genotypes (60.8%), while 40 strains were gH2 (39.2%), mixed type or new genotype was not observed. In infantile hepatitis syndrome (26 clinical isolates were gH1 genotypes, 17 clinical isolates were gH2 genotypes), anicteric hepatitis (25 were gH1, 13 were gH2) and pneumonia (9 were gH1, 4 were gH2), the distribution of HCMV gH genotypes of infantile clinical isolates was consistent with the overall trend (χ(2) = 0.357, P > 0.05). However , the gH2 was more common than gH1 in the clinical isolates of patients with thrombocytopenic purpura (6 were gH2, 1 were gH2, χ(2) = 6.083, P < 0.05).

CONCLUSION

Genotype 1 was the dominant genotype of glycoprotein H in HCMV clinical isolates from our hospital infants. There was no significant difference between the distribution of gH genotypes in infantile hepatitis syndrome, anicteric hepatitis and pneumonia. However, gH2 was the dominant genotype in thrombocytopenic purpura. These findings suggested that there may be a certain relevance between gH genotype and different clinical manifestations.